Hi Tilman, Yes, I want to do that. I'm going to look at the COS tree structure.
Thanks! On Wed, Nov 2, 2016 at 4:10 PM, Tilman Hausherr <[email protected]> wrote: > Am 29.10.2016 um 18:47 schrieb Jonathan Barbero: > >> Hi, >> >> How could I detect any modification between two signatures (visibles or >> not) ? >> >> For example: >> >> An application signs a PDF with PDFbox. A user downloads it, and should >> sign it (visible signature). I would like to check that the user didn't >> add >> any modification after the app signature (except it's own user signature). >> >> How could I check it? I guess it's different between a visible signature >> and not visible. >> > > I assume that what you want is to have something similar to Adobe Reader, > which can detect whether users did more than just add a signature, and then > tells "page X was changed". > > I can't think of a way to do this out of the box. Maybe compare the COS > tree of both PDF structures. > > Tilman > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
